diff --git a/Documentation/ABI/testing/sysfs-driver-sunxi-sid b/Documentation/ABI/testing/sysfs-driver-sunxi-sid new file mode 100644 index 000000000000..ffb9536f6ecc --- /dev/null +++ b/Documentation/ABI/testing/sysfs-driver-sunxi-sid @@ -0,0 +1,22 @@ +What: /sys/devices/*//eeprom +Date: August 2013 +Contact: Oliver Schinagl +Description: read-only access to the SID (Security-ID) on current + A-series SoC's from Allwinner. Currently supports A10, A10s, A13 + and A20 CPU's. The earlier A1x series of SoCs exports 16 bytes, + whereas the newer A20 SoC exposes 512 bytes split into sections. + Besides the 16 bytes of SID, there's also an SJTAG area, + HDMI-HDCP key and some custom keys. Below a quick overview, for + details see the user manual: + 0x000 128 bit root-key (sun[457]i) + 0x010 128 bit boot-key (sun7i) + 0x020 64 bit security-jtag-key (sun7i) + 0x028 16 bit key configuration (sun7i) + 0x02b 16 bit custom-vendor-key (sun7i) + 0x02c 320 bit low general key (sun7i) + 0x040 32 bit read-control access (sun7i) + 0x064 224 bit low general key (sun7i) + 0x080 2304 bit HDCP-key (sun7i) + 0x1a0 768 bit high general key (sun7i) +Users: any user space application which wants to read the SID on + Allwinner's A-series of CPU's. diff --git a/Documentation/devicetree/bindings/misc/allwinner,sunxi-sid.txt b/Documentation/devicetree/bindings/misc/allwinner,sunxi-sid.txt new file mode 100644 index 000000000000..68ba37295565 --- /dev/null +++ b/Documentation/devicetree/bindings/misc/allwinner,sunxi-sid.txt @@ -0,0 +1,17 @@ +Allwinner sunxi-sid + +Required properties: +- compatible: "allwinner,sun4i-sid" or "allwinner,sun7i-a20-sid". +- reg: Should contain registers location and length + +Example for sun4i: + sid@01c23800 { + compatible = "allwinner,sun4i-sid"; + reg = <0x01c23800 0x10> + }; + +Example for sun7i: + sid@01c23800 { + compatible = "allwinner,sun7i-a20-sid"; + reg = <0x01c23800 0x200> + }; diff --git a/drivers/misc/eeprom/Kconfig b/drivers/misc/eeprom/Kconfig index 04f2e1fa9dd1..9536852fd4c6 100644 --- a/drivers/misc/eeprom/Kconfig +++ b/drivers/misc/eeprom/Kconfig @@ -96,4 +96,17 @@ config EEPROM_DIGSY_MTC_CFG If unsure, say N. +config EEPROM_SUNXI_SID + tristate "Allwinner sunxi security ID support" + depends on ARCH_SUNXI && SYSFS + help + This is a driver for the 'security ID' available on various Allwinner + devices. + + Due to the potential risks involved with changing e-fuses, + this driver is read-only. + + This driver can also be built as a module. If so, the module + will be called sunxi_sid. + endmenu diff --git a/drivers/misc/eeprom/Makefile b/drivers/misc/eeprom/Makefile index fc1e81d29267..9507aec95e94 100644 --- a/drivers/misc/eeprom/Makefile +++ b/drivers/misc/eeprom/Makefile @@ -4,4 +4,5 @@ obj-$(CONFIG_EEPROM_LEGACY) += eeprom.o obj-$(CONFIG_EEPROM_MAX6875) += max6875.o obj-$(CONFIG_EEPROM_93CX6) += eeprom_93cx6.o obj-$(CONFIG_EEPROM_93XX46) += eeprom_93xx46.o +obj-$(CONFIG_EEPROM_SUNXI_SID) += sunxi_sid.o obj-$(CONFIG_EEPROM_DIGSY_MTC_CFG) += digsy_mtc_eeprom.o diff --git a/drivers/misc/eeprom/sunxi_sid.c b/drivers/misc/eeprom/sunxi_sid.c new file mode 100644 index 000000000000..9c34e5704304 --- /dev/null +++ b/drivers/misc/eeprom/sunxi_sid.c @@ -0,0 +1,158 @@ +/* + * Copyright (c) 2013 Oliver Schinagl + * http://www.linux-sunxi.org + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * This driver exposes the Allwinner security ID, efuses exported in byte- + * sized chunks. + */ + +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include +#include + +#define DRV_NAME "sunxi-sid" + +struct sunxi_sid_data { + void __iomem *reg_base; + unsigned int keysize; +}; + +/* We read the entire key, due to a 32 bit read alignment requirement. Since we + * want to return the requested byte, this results in somewhat slower code and + * uses 4 times more reads as needed but keeps code simpler. Since the SID is + * only very rarely probed, this is not really an issue. + */ +static u8 sunxi_sid_read_byte(const struct sunxi_sid_data *sid_data, + const unsigned int offset) +{ + u32 sid_key; + + if (offset >= sid_data->keysize) + return 0; + + sid_key = ioread32be(sid_data->reg_base + round_down(offset, 4)); + sid_key >>= (offset % 4) * 8; + + return sid_key; /* Only return the last byte */ +} + +static ssize_t sid_read(struct file *fd, struct kobject *kobj, + struct bin_attribute *attr, char *buf, + loff_t pos, size_t size) +{ + struct platform_device *pdev; + struct sunxi_sid_data *sid_data; + int i; + + pdev = to_platform_device(kobj_to_dev(kobj)); + sid_data = platform_get_drvdata(pdev); + + if (pos < 0 || pos >= sid_data->keysize) + return 0; + if (size > sid_data->keysize - pos) + size = sid_data->keysize - pos; + + for (i = 0; i < size; i++) + buf[i] = sunxi_sid_read_byte(sid_data, pos + i); + + return i; +} + +static struct bin_attribute sid_bin_attr = { + .attr = { .name = "eeprom", .mode = S_IRUGO, }, + .read = sid_read, +}; + +static int sunxi_sid_remove(struct platform_device *pdev) +{ + device_remove_bin_file(&pdev->dev, &sid_bin_attr); + dev_dbg(&pdev->dev, "driver unloaded\n"); + + return 0; +} + +static const struct of_device_id sunxi_sid_of_match[] = { + { .compatible = "allwinner,sun4i-sid", .data = (void *)16}, + { .compatible = "allwinner,sun7i-a20-sid", .data = (void *)512}, + {/* sentinel */}, +}; +MODULE_DEVICE_TABLE(of, sunxi_sid_of_match); + +static int sunxi_sid_probe(struct platform_device *pdev) +{ + struct sunxi_sid_data *sid_data; + struct resource *res; + const struct of_device_id *of_dev_id; + u8 *entropy; + unsigned int i; + + sid_data = devm_kzalloc(&pdev->dev, sizeof(struct sunxi_sid_data), + GFP_KERNEL); + if (!sid_data) + return -ENOMEM; + + res = platform_get_resource(pdev, IORESOURCE_MEM, 0); + sid_data->reg_base = devm_ioremap_resource(&pdev->dev, res); + if (IS_ERR(sid_data->reg_base)) + return PTR_ERR(sid_data->reg_base); + + of_dev_id = of_match_device(sunxi_sid_of_match, &pdev->dev); + if (!of_dev_id) + return -ENODEV; + sid_data->keysize = (int)of_dev_id->data; + + platform_set_drvdata(pdev, sid_data); + + sid_bin_attr.size = sid_data->keysize; + if (device_create_bin_file(&pdev->dev, &sid_bin_attr)) + return -ENODEV; + + entropy = kzalloc(sizeof(u8) * sid_data->keysize, GFP_KERNEL); + for (i = 0; i < sid_data->keysize; i++) + entropy[i] = sunxi_sid_read_byte(sid_data, i); + add_device_randomness(entropy, sid_data->keysize); + kfree(entropy); + + dev_dbg(&pdev->dev, "loaded\n"); + + return 0; +} + +static struct platform_driver sunxi_sid_driver = { + .probe = sunxi_sid_probe, + .remove = sunxi_sid_remove, + .driver = { + .name = DRV_NAME, + .owner = THIS_MODULE, + .of_match_table = sunxi_sid_of_match, + }, +}; +module_platform_driver(sunxi_sid_driver); + +MODULE_AUTHOR("Oliver Schinagl "); +MODULE_DESCRIPTION("Allwinner sunxi security id driver"); +MODULE_LICENSE("GPL");